Friday, November 14, 2008

Vitamins C and E: The Facts Behind the Headlines

By James J. Gormley

Howard Sesso and his Harvard colleagues have just come out with their PHS II paper, “Vitamins E and C in the Prevention of Cardiovascular Disease in Men: The Physicians’ Health Study II Randomized Controlled Trial” (JAMA 300[18]:2123-2133, 2008)

There is even a video in which a couple of the researchers are interviewed ( ). Suffice it to say that it is likely that mainstream media shall have a field day with this paper, regardless of what it says … and what it does not say.

In reference to what PHS II does say — and these are statements that will likely go unacknowledged by most media in the next few weeks — Sesso and colleagues themselves state:

“Moreover, results in PHS II did not corroborate the significant 24% reduction in cardiovascular death or the significant 26% reduction in major cardiovascular events among women aged 65 years or older in the Women’s Health Study.

In addition, the putative increase in hemorrhagic stroke attributed to vitamin E in PHS II, was, according to Sesso and colleagues, “not observed in other primary [de Gaetanoa, 2001; Lee, 2005] and secondary [GISSI, 1999; Yusuf, 2000; Lonn, 2005; Cook, 2007] prevention trials testing individual vitamin E supplement use.”

It is doubtful that these observations will make it into most coverage, however.

What does the established body of research on vitamins C and E really show?

A wide body of scientific evidence has established that taking antioxidant supplements — including vitamins C and E, beta carotene, selenium and zinc — can help reduce the risk of chronic disease.

That being said, we know that antioxidant supplements (and supplements, in general) are not magic bullets, but they can be an important complement to a healthful diet.

A number of landmark epidemiological studies have, in fact, established that vitamin E supplementation reduces cardiovascular disease progression and reduces mortality.

In the Cambridge Heart Antioxidant Study (CHAOS) (Lancet, 1996), investigators wanted to see if supplementation with 400 or 800 I.U. of vitamin E for roughly 510 days would reduce risk for myocardial infarction (MI) and cardiovascular death in 1,035 patients with ischemic heart disease (967 more received a placebo). The findings were that high-dose vitamin E supplementation significantly reduced the risk of cardiovascular death and non-fatal MI.

In a study by Boaz et al. (Lancet, 2000), hemodialysis patients with cardiovascular disease (aged 40 to 75 years) received either 800 I.U./day of vitamin E or a placebo for approximately 519 days. The results? There was a significant decrease in cardiovascular disease (endpoints) and myocardial infarction.

In another study from 2000 (Salonen et al., J Int Med), a combined supplement of both vitamin E and slow-release vitamin C reduced the progression of atherosclerosis in men by 74 percent over a three-year period of supplementation.

In the Nurses’ Health Study (Stampfer, 1993) of 87,000 female nurses over eight years, among the 13 percent of women who regularly used vitamin E supplements (of at least 100 I.U. per day), there was a 31 percent reduction in relative risk for nonfatal myocardial infarction and death from cardiovascular disease compared with women who did not take vitamin E.

In a study by Rimm (1993), in which 39,000 male health professionals were studied for four years, 17 percent of the men took vitamin E supplements. Of those who took the highest doses (median of 419 I.U. per day) had a 40 percent reduction in the relative risk for nonfatal myocardial infarction or death from coronary hearth disease.

That’s what the science really shows.

While every study, even those with null results, can contribute to the body of knowledge regarding nutritional supplementation and prevention of chronic or acute disease, it is always unfortunate when studies produce anomalous findings that contradict the already well established evidence that antioxidant vitamins are critical for health promotion, disease prevention and treatment.
The Gormley Files - Blogged